Sodium chlorate, NaClO3, being a powerful oxidizing agent, is used in the manufacture of matches and soft explosives, in calico printing, as a garden weed killer, etc. Heretofore, it has typically been prepared by the reaction of chlorine on hot, concentrated sodium hydroxide. The sodium hydroxide in turn being made from the electrolysis of brine (NaCl+H2O) using one of a variety of diaphragm cells.
The byproduct stream of a sodium chlorate electrolysis cell contains hydrogen and oxygen, some chlorine and organics. The sale of the hydrogen would be economically effective if it were pure, but the purification of the hydrogen to a suitable commercial grade is prohibitively expensive.